Apparatus for measuring frictional resistances between bodies in sliding contact.



No. 634,007. Patented Oct. 3, I899.

A. B. LAWTHEB.

vAPPAIHU'US FOR MEASURING FBIGTIONAL BESISTANCES BETWEENBODIES IN vSLIDING CONTACT.

(Application and my. 14, was. (No Model.) 5 Sheets-Sheet L Ef'al14418566 is: I 7 Q ,I/v VEN TOR;

04111750 IaLHM THER.

HM I rra RIVEYS .mmmcmmmmc' No. 634,007. Patented on. 3, I899.

4 A. Bi LAWTHER.

APPARATUS FUR MEASURING FRICTION AL BESISTANOES BETWEEN BODIES/I SLIDINGCONTACT.

Amman mu 1m. 14, was.

- 5 Shuot s--Shut 2 WITNESSES. JNvE/v TO/R.

Jar/PE) BinwTHsR Jaw 4 M I m 22%:- 775W,

mcflrToRA Em.

11-1: mums PETERS 0c, mew-mun. wasumcmw u. n

No. 634,007. Patehted Oct. 3, I899.

A. B. LAWTHER. APPARATUS FOR MEASURING FBICTIOIIAL BESISTANCES BETWEENBODlES I N SLIDING CONTACT.

(Applicnfion flied LL14, 1898.)

- 5 Sheets-Sheet 3,

(lo Iodel.)

Wrmmsszs: l/v VEN TOR! I .AYLFRED BLAWTHER ma NDRmS Pzrzns no.PHOTMITHO" wasumo'rou. n. :4

No. 634,007. V Patented Oct. 3, 1899.

A. B. LAWTHER.

APPARATUS FOR MEASURING FBIGTIONAL BESISTANCES BETWEEN BDMES IN 8L IDINGCDNTAGT.

(Applicntion filed In. 14, 1898.;

(I0 Modal.)

v 5 Sheets-Shani 4,

WITNESSE-S JNVE'NTOR.

A flu-R521 E1 L/IWTHER B M His 1 ronzvsv's.

No. 634,007. Patented Oct. 3, I899. I A. a. LAWTHER. APPARATUS F08MEASURING FBICTIONAL 'RESISTANCES BETWEEN BODIES IN SLIDING CONTACT.

(Applicatioxi filed I". 15, 1898.)

5 Sheets-8hent 5.

(No Model.)

BY%44,A/@I V 7 1m: jrrolwvsvs.

Y some [ST TES PATENT OFFICE;

ALFRED B, LAWTHER, OF SYRACUSE, NEW YORK.

APPARATUS FORMEASURING FRlCT IONAt RESISTANCES BETWEEN Booms m suomeCONTACT.

SPECIFICATION forming art or Letters Patent No. 634,007, dated October3, 1899.

Application filed March 1 4, 1898.

To all whom it may concern: 7

Be it known that I, ALFRED B. Lnwrnnu, a citizenof the UnitedStates,'residing in Syracuse,in the county of Onondaga and State of NewYork, have invented a new and useful Improvement in Apparatus" forMeasuring Frictional Resistances Between Bodies in Sliding Contact, ofwhich the following is a specification.

This apparatus is designedfor the purpose, among other things, ofdetermining the value of lubricating substances, oils, 850., and of thevarious antifriction-bearings of all kinds.

The principle upon which the operation of the apparatus depends is, Ibelieve, a newlydiscovered one and never before applied to any machine.I'have observed, and doubtless many thousands of people have observedthe same thing, that when a machinist desires, for example, to force atight-fitting pulley upon a shaft which he cannot slide on in a straightmovement-he resorts to the expedient of wringing it on, asit is termedthat is to say, he will secure the shaft firmly in a fixed position andthen apply a portion of his; force in the form of pressure tending toslidethe pulley along the shaft and simultaneously another to rotate thepulley on the shaft, and by this helical movement he is able to get thepulley upon the shaft, which he could not do by astraight movement. My

' measuring apparatus is designed tooperate upon a principle somewhatanalogousto this workmans expedient; and it consists, essentially, in arevolving shaft mounted in a position inclined to thehorizon'r Thedegree of inclination is such that the weight of the shaft when the sameis not revolving will be insuificient to cause the shaft to slide; butwhen the shaft is revolved the power causing the revolution operatingsimultaneously with the weight of the shaft will be sufficient toovercome the resistance of the bearings and the shaft will move slowlyendwise through the bearings. Of course the sameresultwill be producedif for the power of gravity a spring is substituted, in which case theshaft may of course be made perfectly horizontal and the amount of powerapplied in the end wise direction be regulated by the tension of thespring instead of the inclination of the sen-n Nonvavse. (No model.)

shaft, and where throughout this descriptionl speak of the inclinedshaft or inclinabl'e shaft it is to be understood that I mean a shafthaving. applied to it a force which tends to move it endwise, but whichis notsufiiciently great to so move it unless accompanied by a I pidityof the-endwise movement imparted to thenapplied in the oppositedirection alterhately. This alternation gives a long-continuedoperationof the apparatus without the necessity of having a shaft of unwieldlylength. Y

' It may serve to make the principle of my apparatus clearer to state itin terms divested of mechanism and form, so far as such divestment maybe readily conceived, as follows: Suppose a smooth metal plate with aplane surface be lying in a positionnearly horizontal, but with a slightdeclination toward the west. Suppose that upon this plane surface thererests a metal block, the declination of the plane being so slight thatthe block will not by its own weight slide toward the west. Now supposea power of some sort-say a string tied to the blOclP-isappli'ed to movethe block toward the north. Then in that case as soon as the block isunder motion its weight will cause it to travel not exactly north,

but in a line a little west of north, in the ditcrmincd and from whichas a corollary the relative frictional resistance of the slidingsurfaces upon each other may be computed.

In the accompanying drawings, which form a part of this specification,and in which similar letters of reference indicate like parts throughoutthe several figures, I show an apparatus in which the endwise forceapplied to the shaft is the force of gravity due to a slight inclinationof the shaft.

In said drawings, Figure 1 is a plan view of the apparatus. Fig. 2 is-anend elevation showing that end of the machine which carries the inclinedshaft. Fig. 3 is a side elevation. Fig. 4 is a vertical section on theline 4 t of Fig. l. on the line 5 5 of Fig. 1', and Fig. 6 is asectionalview of one of the compressed-air cylinders for reversing theinclination shaft.

In said drawings, Ais the stationary frame of the machine. Mounted onthis frame at one end is the shaft B, carrying the drivingpulleys B anda belt-pulley or drum 13 This shaft and its appurtenances may be mountedon a movable bed B which serves as a belttightener by reason of thespring 13 and the tightening-screw B At the other end of the machine isthe oscillating carriage G, mounted on the long trunnion or shaft 0 inthelongitudinal bearing 0 riage are the bearings D, to be testedthemselves or to contain the lubricating material which is to be tested,and mountedin these hearings D is the testing-shaftv E, free to slideand also to rotate in said bearings D, and mounted on this testing-shaftis the bandpullcy E, from which a band E passes to the driving-drum BMounted on the upper portion of the oscillating frame 0 is a pointerarm0 which indicates on the arc-plate C fixed to the stationary frameworkof the machine, the arc of inclination of the testingshaft E, and fromthe lower portion of the frame 0 extends an adjusting and operating armC the lower end of which 0 moves between the two adjusting stop-screwsCO fixed to the stationary frame of the machine and adjustable to limitin both directions the arc of oscillation of the said oscillating frame,and consequently the amount of inclination of the testing-shaft E ineither of its two positions.

To avoid confusion from the other elements of the machine, we may stopto consider its operation in connection with the parts alreadydescribed. Suppose power to be applied to the driving-shaft B andtransmitted by the belt and pulley to the testing-shaft E at a givenrate of revolution and suppose the testing-shaft to stand at theposition and inclination shown inthe drawingsthat is to say, at suchinclination that its own weight Will not causesaid shaft to slideendwise when not rotating. Then when said shaft begins to revolve itwill also begin to slide slowly of the down its incline, and the speedof this descent Fig. 5 is a sectional viewtaken In this oscillatingcar-- will be the measure of the frictional resistance in the bearings,and this by proper devices may be recorded in a graphic report, as willbe readily understood and as will be subsequently explained when we cometo consider that part of the machine.

As a convenient, simple, and easilyoperated means for changing theinclination of the testing-shaft by tipping the oscillating frame 0 inone direction and then in the other alter nately at each descent of thetesting-shaft I provide two cylinders. G G, each provided with a pistong, connected to the oscillating frame, and each having a valve andvalvestem 9. These cylinders are connected to a compressed-air reservoirG by suitable piping, and an air-pump G may be provided to keep withinsaid reservoir a supply of compressed air. The valves of the twocylinders arev operated by magnetsH H, connected in circuit with abattery H and two pairs of contact-points H 11 one pair at each end ofthe oscillating frame in position so that when the end of the test-shaftE reaches its. lowest point it will touch the two contact-points andclose the circuit through one or other of the magnets H H, which willattract its armature, attached to t-he valve-stem, and reverse thepositions of the valves in the two cylinders G G, causing the pistonsand piston-rods to reverse their position and swing the oscillatingframe, thus reversing the inclination of the testing-shaft at theinstantit has reached the lowest point in its fall. Other well-known mechanismmay be employed for this purpose, as Will be apparent to those skilledin the arts, the only requirement being that the mechanism for reversingthe position of the shaft should be brought into operation at theindeterminate time when the shaft has reached its lowest position inboth directions alternately.

To produce and present a graphic record of the operation of the machine,I introduce a clock or time mechanism, which carries a sheet of paper ina circular path at a stated rate of movementsay one revolution per hour.The case for the time mechanism is indicated at J, and the paperrecord-sheet at J. I have not shown a construction of clock itself, asthis will be readily understood by anybody Without illustration. At K isa pen or pencil point bearing on the paper of the dial and carried onthe lever K, the lower end of which is pivoted at K A rod K connects thelever K with the bell-crank lever K pivoted at K to the pointer-arm CThe other end of the bell-crank lever K is pivoted at K to a stem Kentering a thermometer-tube L, and the pivot K of the lever K islikewise upon a similar stem K of the thermometertube L. The bulb of thethermometer L is 56 .907 [if l 1 is as follows: The pcncilK, becausoofthe re 5 v v In order that a simultaneous record of-the tation'of thepaper record-sheet J, traces a circular line upon said sheet until themoment when theinclination of thetestingshaft is reversed by theswinging of the oscillating frame, at whichtime the pointer C movingwith said oscillating frame, carries the lever K bodily over eithertoward or away from the recording apparatus, causing said pencil K totrace a line of a radial character, and then the continuation ofthecircular movement of the sheet begins again and continues until thenext oscillation, when another radial line is traced in the oppositedirection, andso on as long as the machine is running. The re suitingfigure traced upon the sheet will roughly resemble the teeth of thegear-wheel,

reach tooth indicating a'reversalof the inclination'of the testin-shaft, and this affords a means for counting the number of reversalswhich havetaken place in a giventime, The timehours, minutes, andseconds n1ay be printed or marked uponthe record-sheetin equal-spacedradial'tlines, which to avoid confusion are not shown in the drawings.

' temperature of the bearings under examination may be kept, the twothermometers L L above mentioned are provided. The then 'mometer L, withitsbulb located in the'bearing itself, denotes its temperature, and thisis conveyed to the record-sheet by the movement of'the stem K any riseinftempera-- tnre lifting said stem and moving the ,bellcrank lever Kthe result of which is to throw the pencil K out toward the periphery ofthe record-sheet. To get at the actual temperature, however, of thebearing, 1 provide for subtracting from this motion the atmospherictemperature. This is done by the thermometer L, whose bulb is located inthe open air. Its stem K being connected to the pivot K positions thepencil K to a point representing the difierence between the atmospherictem perature and the temperature of the bearing D, for any rise in theatmospheric temperature by pushing out the stem K will tend inproportion to throw the pencil K in toward the center ofthe'record-sheet, and the record-sheet J may be provided with concentriclines printed or marked thereon to indicate the temperature, which willbe read by noting between which of the concentric lines (not shown inthe drawings) the circular marks of I the pencil K occur, and thus anyfall or rise of the temperature during the operation of the machine isduly recorded. For convenience of seeing at any time and withoutreference to the recording apparatus above described the actualtemperature of the bearing I prefer to provide a third thermometer Lwhich may be read in the ordinary way by the position of the mercury inits tube.

To provide for a predetermined and adj nstable pressure on thetesting-shaft in its bearings, which is also or may be a factor in making tests of bearing and lubricating material, I

I makeia part 1 of oneor bothjo ffthelocal-Q in gsjl) rmovableandapply'a pressure device. 7 V

thereto forpressing this movablepart of the bearing against the shaft,This'pressu're dev vice may consist, of-arspring with a screw tensiondevice for increasingits tension in'a regula'l'ale way. or othersuitable mechanism;

but Iip'refer to employ air.- pressure for this purpose,fa '11.d I haveshown sucha device in the drawings; M is a cylinder containing apistouM, the'pisto1'1-rodM?of whichsetsinto themovable bearing, part D;A pipe M is carried to the trunnion-shaftU-and through I the centerof'this shaft to the air-reservoir G so that a stated "pressure is broughtto bear upon said. bearing-plate D. this pressure may beregulated toanydesired amount, I provide anordinary pressure-regulating valve M on thepipe: M and that the amount of. pressure employed may be indi- In orderthat cateda pressure-gage M (see Fig, 3) is proyided, and as a' furtherguaranteethatthe' rec' uired-pressure shall never be exceeded aregulable safetyvalve M? may be applied to: I

the pressure-cylinder M. f V The machine shown in thedrawings isspecially designed for testing lubricating-oils,

fats,-and such like materials.

Where .it is desiredto test the frictional qualities of d if-- I fferentmetals in bearings, it would be desir-x able to have somereadier meansfor removing the bearings D and replacing them rapidly than is shown inthe machine indicatcd;but itis notnecessary here to describe suchincidental changes in construction, because any mechanic will know howthis maybeidonel 1-@mm V 1. The means for measuring frictionalresistance between bodies in sliding contact, which consists in arevoluble shaft mounted in bearings and free to slide endwise in saidbearings,and having a force applied to revolve the shaft and anotherforce applied to slide the shaft end wise, the latter force beinginsufficient to slide the shaft except when said shaft is revolving, theshaft being free toslide in either direction and the force to slide thesame being applied alternately in opposite directions, combined withmeans for recording on a timesheet said alternations,

and also with means for simultaneously recording on the same sheet thetemperature of the bearings of said shaft, substantially'as specified 2.'The improvement in the art of measuring the frictional resistance ofsliding surfaces of bodies, which consists in sliding one of thesurfaces upon the other by the application to the movable body of twounequal forces at an angle to each other, one of said forces beinginsufficient to move the body when at rest, and the other being greater,the measures of frictional resistance being determined by the extent oftheinfluence of the lesser force upon the movement, substantially asspecified.

3. The means for measuring frictional re- ICO.

sistancc between bodies in sliding contact, which consists in arevoluble shaft mounted in bearings and free to slide endwise in saidbearings, and having a force applied to re- 5 volve the shaft andanother force applied to slide the shaft endwise, the latter force beinginsufficient to slide the shaft except when said shaft is revolving, thelatter force being the attraction of gravitation utilized by giving theshaft an inclination from the horizon,

substantially as specified.

t. The means for measuring frictional resistance between bodies inslidingcontact, which consistsin a revoluble shaft mounted (5 inbearings and free to slide endwise in said bearings, and having a forceapplied to revolve the shaft and another force applied to slide theshaft endwise, thelatter force being insufficient to slide the shaftexcept when 2o said shaft is revolving, thelatter force being theattraction of gravitation induced by giving the shaft an inclinationfrom the horizon, the shaft being free to slide in either direction, andmeans for alternately applying the attraction of gravitation to slidethe shaft in opposite directions, consisting of means for reversing theinclination of the shaft, substantially as specified.

5. The means for measuring frictional re- 0 sistance between bodies insliding contact, which consists in a revoluble shaft mounted inbearings, said bearings being mounted in an oscillating-frame to givethe shaft inclination to the horizon alternately in opposite di- 5reetions, and means for automatically oscillating said frame, said meansbeing governed and controlled by the endwise movement of the shaft,substantially as specified.

G. The means for measuring frictional resistance between bodies insliding contact, uio \VlliCh'OOlllSlStS in a revoluble shaft mounted inbearings and free to slide endwise in said bearings, said bearings beingmounted in an oscillating frame, to givethe shaft inclination to thehorizon alternately in opposite directions, and means for automaticallyoscillating said frame, said means being governed and controlled by theendwise movement of the shaft closinga'n electric circuit, substantially as specified.

7. The means for measuring frictional resistance between bodies insliding contact, which consists in a revoluble shaft mounted in bearingsand free to slide endwise in said bearings, said bearings being mountedin an oscillating frame to give the shaft inclination to the horizonalternately in opposite directions, and means for automaticallyoscillating said frame, said means being governed and controlled by theendwise movement of the shaft, the means for oscillating said frameconsisting of a pair of oppositely-operating engine-cylinders and theirpistons, substantially as specified. v

8. The combination with the revoluble 6 shaft free to slide endwise, andhaving means for inclining the same in opposite directions, of means forincreasing the pressure between the said shaft and its hearing, whichconsists in making a portion of the bearing movable and connectingtherewith a device for producing regulable pressure thereon, said deviceconsisting of a compressed-air cylinder, substantially as specified.

' ALFRED B. LAWTHER Witnesses:

H. M. MUNDAY, I D. BARSTOVV.

